Past Australian tennis champions say Stosur's first grand slam win is a sign of more greatness to come.

Simon Lauder reports.

SIMON LAUDER: The 13-time grand slam champion Serena Williams wasn't the only one left stunned as the ninth seeded Australian overpowered her.

COMMENTATOR: Inside out forehand. Serena can't get there and Samantha Stosur - are you kidding me? - has taken out Serena Williams in straight sets to win the US Open finals 6-2 and 6-3 in an hour...

SIMON LAUDER: Twenty-seven year old Stosur is the first Australian woman to win the US Open in 38 years.

SAMANTHA STOSUR: Yeah I didn't start playing to break records or anything like that. My goal and dream since I started, I've said it before, was to win a grand slam. And now to actually do it and it's unbelievable. And being an Australian with that great history and now to break that drought is obviously very special.

SIMON LAUDER: Stosur came close to winning her first grand slam at the French Open last year and her father Tony Stosur says the win has been a long time coming.

TONY STOSUR: She really deserves it. After her disappointment at the French tour I mean it's terrific comeback. So hope for better and better things!

SIMON LAUDER: While Stosur played the tennis of her life Serena Williams seemed stunned. It was the first time she'd played at Flushing Meadows since a tirade in 2009 that earned her a two year probation. And now she could be fined or banned again for violating that probation.

When Williams was docked a point for shouting out "come on" just as Stosur was trying to return a shot she directed her feelings at the umpire.

SERENA WILLIAMS: You give a code violation because I express who I am? We're in America last I checked. Really don't even look at me. I promise you don't look at me.

SIMON LAUDER: Williams will find out on Monday whether her outburst will lead to further punishment.

After the match Williams was more graceful and said she didn't remember much about the incident.

SERENA WILLIAMS: Oh I don't know. I don't think it had a big impact because I think at the end she won pretty handily, like 6-3, so maybe it would have been 6-4, I don't know. (Laughs) But I think you know like I said I give her all the credit because she played, she really played phenomenal and she deserved to be the US Open champion this year.

SIMON LAUDER: Australia now has a women's grand slam tennis champion for the first time since Evonne Goolagong Cawley won Wimbledon in 1980.

Goolagong Cawley says she's very proud.

EVONNE GOOLAGONG CAWLEY: I've never seen her look so fit. She was moving well on the court. In fact I actually do call her twinkle toes because she, a few years ago she wasn't moving that well.

SIMON LAUDER: For a long time Sam Stosur was better known as a doubles player. But former professional player now Federal MP John Alexander has long predicted she would win a grand slam event on her own.

JOHN ALEXANDER: She will continue to improve or play at this level. Playing at this level I think, you know, most people now think that she has a chance at every grand slam.

SIMON LAUDER: What will it mean for women's tennis to have an Australian champion for the first time in what, 31 years?

JOHN ALEXANDER: Hopefully more and more kids take up the game and we'll produce more Sam Stosurs.

SIMON LAUDER: The next big event on the tennis calendar is the Australian Open. Sam Stosur has acknowledged that the expectations will now be huge.

SAMANTHA STOSUR: I guess we'll see how I handle it when the time comes. But if I can try and play like I did today then hopefully it's all going to be okay.

SIMON LAUDER: Stosur will now return home to Queensland $1.8 million richer.